The present invention relates to a curtain airbag in which a curtain-shaped airbag portion is deployed at the inner surface side of a side window glass. More particularly, the present invention relates to a curtain airbag which has the advantage of, for example, precisely deploying a bag portion along a side window glass.
In the curtain airbag, a curtain-shaped airbag portion is deployed at the inner surface side of a side window glass beside an occupant at the time of an emergency of a vehicle. By the deployment of the curtain-shaped airbag portion, shock that is exerted on the occupant when the occupant collides with a side surface of the vehicle is absorbed or the occupant is prevented from being thrown out of the vehicle during a roll-over of the vehicle.
FIG. 10(A) is an exploded perspective view of the structure of a conventional curtain airbag, and FIG. 10(B) is a side sectional view of FIG. 10(A).
A curtain airbag 100 shown in FIGS. 10(A) and 10(B) comprises a bag body 101. The bag body 101 is a bag-shaped body that is formed by placing two sheets to be piled each other and joining them together by sewing, bonding, or welding. In a normal condition before deployment, as shown in FIGS. 10(A) and 10(B), the bag body 101 is folded up in bellows. Ears 101A are formed at a top edge of the bag body 101. Although only one ear 101A is shown in FIG. 10(A), a plurality of ears 101A, for example, seven ears 101A, is formed on the bag body 101 at predetermined intervals in a longitudinal direction of the bag body 101. Holes 101a to 101c are formed in each of the ears 101A.
The bag body 101 is accommodated in a sleeve-shaped cover 103, which is rectangular in a cross section. A slit is formed in a top edge, i.e. left top edge in FIG. 10(B), of the cover 103. The ears 101A of the bag body 101 are pulled up outward from the slit. As shown in FIG. 10(B), a tear line 103a is formed in the bottom surface of the cover 103 along a longitudinal direction thereof. When the bag body 101 deploys, the tear line 103a is ruptured, so that the bag body 101 deploys downward from the cover 103. The cover 103 in a condition of receiving the bag body 101 at the inside thereof is disposed along the roof side of the vehicle.
Hangers 110 are mounted to the ears 101A of the bag body 101. The hanger 110 includes a rectangular inner plate 111 and a rectangular outer plate 112. The inner and outer plates 111 and 112 are linked by a corresponding linking portion 113. Each ear 101A of the bag body 101 is sandwiched between the corresponding inner and outer plates 111 and 112 (refer to FIG. 10(B)). Holes 111a and 112a are formed in the center portions of the inner and outer plates 111 and 112, respectively.
A pawl 111b is formed at the right edge of each inner plate 111. A pawl 112b is formed at the left edge of each outer plate 112. In the condition that the hanger 110 is mounted, the pawl 111b of the corresponding inner plate 111 is folded after being inserted into the hole 101b of the corresponding ear 101A, and the pawl 112b of the corresponding outer plate 112 is folded after being inserted into the hole 101c of the corresponding ear 101A. A bolt (not shown) for mounting the curtain air bag 100 to the body of the vehicle is inserted into the holes 111a and 111b of the hanger 110 and the hole 101a of the ear 101A of the bag body 101.
An inflator 105, shown in FIG. 10(A), is connected to an open end of the bag body 101. A cap 106 covers an end, i.e. right end in FIG. 10(A), of the inflator 105. The cap 106 is ruptured by the pressure produced by ignition of the inflator 105. The end of the inflator 105 covered by the cap 106 is secured to the open end of the bag body 101 by a clamp band 108. The inflator 105 is supported at both sides inside a retainer 107. The retainer 107 is secured to, for example, an A pillar of an automobile by screws 109 while supporting the inflator 105.
In the above-described conventional curtain airbag 100, when deployment gas is supplied into the bag body 101 from the inflator 105, the bag body 101 is inflated, so that the tear line 103a of the cover 103 is ruptured, causing the bag body 101 to deploy. At this time, reaction force produced by the deployment of the bag body 101 is received by the ears 101A of the bag body 101 and the hangers 110. However, the deployment direction of the bag body 101 itself is not restricted very much, so that there is a tendency for the bag body 101 to deploy towards the inside of the cabin of an automobile. Therefore, the bag body 101 may not deploy smoothly along the inner surface of a window glass.
The present invention has been made in view of the above-described problems and has as an object the provision of a curtain airbag which has an advantage of being capable of precisely deploying a bag portion along a side window glass.
Further objects and advantages of the invention will be apparent from the following description of the invention.
To overcome the above-described problems, according to a first aspect of the present invention, there is provided a curtain airbag in which a curtain-shaped airbag portion is deployed along an inner surface side of a window glass, i.e. side window glass, beside an occupant at the time of an emergency of a vehicle. The curtain airbag comprises a bag body; an inflator connected to one end of the bag body for supplying deployment gas; a cover which covers the bag body; a hanger connected to a top end portion of the bag body, which is used to hang the bag body from a structural member of the vehicle; and a restricting member which restricts the deployment direction of the bag body so that the bag body deploys along the inner surface of the window glass.
According to this aspect of the present invention, since the deployment direction of the bag body is restricted by the restricting member, it is possible to smoothly deploy the bag body along the inner surface of the window glass.
According to a second aspect of the present invention, there is provided a curtain airbag in which a curtain-shaped airbag portion is deployed at an inner surface side of a window glass, i.e. side window glass, beside an occupant at the time of an emergency of a vehicle. The curtain airbag comprises a bag body; an inflator connected to one end of the bag body for supplying deployment gas; a cover which covers the bag body; a hanger connected to a top end portion of the bag body, which is used to hang the bag body from a structural member of the vehicle; and a receiving member provided along the top end of the bag body, which receives reaction force produced when the bag body deploys downwards.
According to this aspect of the present invention, the receiving member receives the reaction force produced when the bag body deploys in the downward direction, so that deployment force of the bag body can be concentrated in one, downward direction. Therefore, the bag body smoothly deploys along the inner surface of the window glass. In addition, as a result of the bag body deploying precisely in one downward direction, it is possible to reduce variations in the deployment time of the bag body.
In the curtain airbag of the present invention, the member may be a plate which is provided along the top end of the bag body and which extends substantially perpendicular to the window glass. In this case, by using the plate, reaction force produced when the bag body deploys downward can be precisely received. In addition, when the member is a plate, the structure is simplified, so that it can be easily formed.
The curtain airbag of the present invention may further comprise an inner-surface-side member or skirt that extends down from an occupant-side edge of the plate. In this case, the inner-surface-side member prevents the bag body from protruding towards the inner side, i.e. opposite to the structural member side, when the bag body deploys. Therefore, the bag body deploys more precisely in the downward direction.
In the curtain airbag of the present invention, the restricting member or the receiving member may be provided at the hanger. In this case, the number of component parts used is not increased, thereby making it possible to simplify the structure of the curtain airbag.